This is going to focus on world-building for high fantasy worlds, but you could probably apply most of these to other genres, too.

These are basic steps to follow when creating a world. You can actually write down every single detail of the following (which is what I'd recommend if you're writing high fantasy) or just keep organized in your head if you're capable of it.

Magic is usually an exception to everything in world building. If your magic system allows for you to break the rules I'm stating here, by all means, break them. Just keep it believable and within the constraints of your world. If one army is able to teleport to the other side of the world, make sure the other armies (unless you have a good reason for it) can do this, too. Keep everything consistent.

1. Create a world map.

You don't have to be an artist to draw circles, squares and triangles. Just get a basic feel for your world. Plan out what countries are where, the geography (mountains, rivers, lakes, deserts, grasslands, rainforests, etc.), and strategic locations for cities (generally near rivers or big bodies of water, unless your world has a way to transport water effectively). Plan the geography into a way that makes sense. You probably can't have a desert right next to a rainforest (again, if your world can somehow break that rule, go for it). Just keep it believable.

2. Come up with general cultures for the cities/areas of civilization.

A city next to the ocean/lake/river would probably be a port city. There would be ships, and it would be a major point of trade. You'd probably have very ethnically diverse people living or just passing through. A city in the desert would have clothes that cover them completely to protect them from sunburn. They'd have ways to get water (or maybe they live in or near an oasis). A city in a forest would have a lot of objects made of wood, so they'd need woodcutters. Don't forget hunters. A civilization in the arctic would probably be very eskimo-like with thick clothes made from animal skins.

3. HISTORY, HISTORY, HISTORY.

Before you do anything else at this point, plan out the histories of your world. Most of this won't even make it into your novel, but it's a very good idea to have an idea of how things came to be. Hints of that would slip into your writing and make the world seem a lot more believable. Was there recently a civil war in a country? That would affect how the people react to each other and to outsiders. Had they been attacked in the past and are now reserved toward outsiders? Are they closed off from the outside world? If another country has a magical fountain that gives them something important, what is the history behind that? How did they find the fountain? What happened when they found it? Another country could have a scandal in the aristocracy. How did their governments come to be? What are their governments?

Make a timeline of world events to keep your dates straight. Don't have two world wars within two months of each other and the next day they go into an era of peace and prosperity. Again, keep this believable.

Remember, the events happening in one place will effect people all over the world.

A war in one country will put resource strains on other countries, or maybe they'll be making money off the war. Everything in the world is interconnected, so please keep that in mind. Think of our world. A terrorist attack somewhere will have financial and emotional impacts on people across the globe. This is the hardest point for me to explain, so please let me know if you need further examples. :)

4. Plan the cultures you've come up with in much greater detail.

This is by no means an exhaustive list of questions to ask yourself, but it's a springboard to base your ideas on. Be as detailed as possible in the following areas. You can never develop your world too much. It's those tiny details that make a world memorable.

Cultures consist of:

Food

-What foods do they eat?

-Each social class should have different foods available to them. A peasant wouldn't be eating roasted pheasants every day.

-How they obtain food? Hunting, importing, stealing?

-What are special foods during festivals and celebrations?

Religion

-Do they worship a god? Gods? Spirits? Animals? Other deities? Are they atheists?

-How do they worship?

-What rituals do they have?

-How often do they worship?

-Where do they worship? At home, temples, sacred places that have spiritual meaning?

-Do they have objects to worship or worship with? (rosary, statues, etc.)

-What happens if they DON'T follow the rules of their religion?

-What are the morals their religion teaches?

-Are there other sects or divisions/branches of the religion?

-Are there people of that culture who don't agree with the religion?

-Do they have special clothes or outfits when worshiping?

-What is the religious hierarchy? (such as the priests and pope in Catholicism) Are certain people more important in their society than others because of this? Are certain people at the complete bottom (such as untouchables of India)?

-Do they have a medium who is "closer to god" than the average person and worships for them? (such as a priestess or shaman)

-Do they use their religion as a form of healing illnesses? (witchdoctors)

-Do they connect with spirits of the dead?

-How old is the religion (this goes into creating histories)?

-What are their ceremonies, celebrations, festivals? What are they based on and how are they executed? Dancing? Parties? Get drunk? Floats? Decorations? Candles? Sculptures? Try to think of really unique ways to celebrate something.

-How do they please the gods? Sacrifices? Cannibalism? Not sinning? What happens if they DO sin?

Remember, religion is usually deeply embedded in a person's lifestyle, whether they're aware of it or not. Maybe they have a saying that means "may god watch over you" or something. Maybe they have certain gestures that reveal some form of worship.

Social hierarchy

How is the society organized? Remember the social pyramids from history class? King at the top, workers at the bottom, and there are a LOT more workers than kings. How are your world's cultures set up? Who is their ruler or leader?

Government

This is kind of common sense, but make sure not to make two cultures the same. Don't give them the same government unless you have a reason for it. In the real world, the US's government is very different from, say, a dictatorship.

-Who is their leader/ruler/king?

-How are they chosen? By the people? Through birthright? By strength? Through a contest or competition?

-Who makes the laws? The ruler? His/her subordinates? The people?

-Who enforces the laws? Is there a type of police force? Guards? Patrols?

-What happens if a law is broken? Jail? Stocks? Death? An eye for an eye? Do the people who were hurt in the crime decide on the punishment?

-Are law breakers considered scum, or are they hailed as awesome rebels?

Military

-Most countries require a military in order to protect themselves from attack of other nations. Sometimes, your nation may reside in a peaceful era or location, or maybe the inhabitants don't believe in fighting, so they may not have a military.

-Most countries require a military in order to protect themselves from attack of other nations. -Sometimes, your nation may reside in a peaceful era or location, or maybe the inhabitants don't believe in fighting, so they may not have a military. Still, don't forget about them.

-Fighters and soldiers are usually needed not only for protection from other nations and organizations, but also for internal conflict. You've probably heard of the American Civil War, yes? Even during protests, the government sometimes sends SWAT teams or soldiers to control the crowds if fights break out and they get too rowdy. Even if the country/kingdom/city/territory doesn't have enemies, its people probably won't be 100% happy with everything their government does. When that happens, protests happen and fights break out.

-Keep the size of your army in mind. A city with a population of 10,000 won't have an army of 9,000 men. There will be civilians-elderly, children, sick, wounded. Keep the size of the army proportional to the population of the place.

-Who are the soldiers? Men? Women? Children? Teenagers? Who's allowed to join? What happens if someone who isn't allowed to join tries anyway?

-How does someone get into the army? Is there a draft or do they volunteer?

-Think about the social aspects of this: are the soldiers revered and respected, or feared? Are they just and fair, or do they abuse their power? Are certain people expected to join the army? If they don't, are there severe social consequences (eg. Loss of respect, disowned by parents, etc.)?

-What weapons do they use? Keep the distribution of resources in mind. If an army is made up of hundreds of thousands of soldiers, it's not likely that every single one of them has the best weapons known to man. The less experienced recruits will probably get cheaper weapons. The generals would get the really fancy stuff.

-What is the chain of command of the army? Who's giving the orders? Does he/she have a replacement/right hand man? An adviser?

-What is the fighting style? Combat strategies? This is really important in giving the army as a whole a personality. Do they rush in head-on or use Guerrilla-type warfare where they fight from the shadows and sabotage the enemy? Do they surround their enemy like a pack of wolves?

-Training-don't forget to train your soldeirs! How do they train? Where? What do they do? Is it like boot camp where they run around and go through obstacle courses? Do they spar with each other? How do they practice their skills? Who teaches them?

-Food, water, and shelter! Very important! When an army is on the move, they need basic things like this. If they're a huge army, they probably will just eat bread, cheese, and water. No five-star banquets. Again, distribution of resources. A general might be eating a roasted pheasant for dinner, but the pawns will probably eat something a little better than dirt unless the nation is REALLY wealthy. When they travel, try to make them travel along the path of a river or lake so they have access to clean water.

-Travel-armor is extremely heavy, so they wouldn't be able to carry much with all that weight. If they travel using horses, try not to work the poor things to death by making them carry three sets of armor each and a suitcase of clothes and several packs of food.

-More on traveling-moving a big army of thousands or even hundreds will NOT be quiet. They'll be clanking around in their armor and the horses will be neighing and such. They'll probably be moaning and groaning about how their feet hurt, too. Don't think a huge army can move across the nation in two hours and surprise attack the enemy. Unless they're all well-versed in stealth techniques, this just isn't possible.

-Expanding on timeframe-moving thousands of men takes TIME. You can't have them running the entire trip and travel several hundred miles in a few hours (unless they have some kind of magic transportation system, of course.) Keep it realistic. When I'm walking with a twenty-pound backpack, I walk a lot slower than if I'm not carrying anything. If these soldiers are carrying armor, which is excruciatingly heavy, they probably won't move too fast, even with horses or other animals. They'll get tired and need to rest after a while. Don't have them travel all day and then fight all night. Put yourself in their shoes; if you can do it, so can they (usually). If you can't feasibly do it, don't try to make your soldiers do it.

Recreation

-What do they do for fun?

-Games?

-Dancing?

-Arts and crafts?

-Sports?

-Competitions? (There's one culture that grooms chickens and then battles them to the death. It's a HUGE sport for them, and people go to great lengths to raise their prize chicken, treating it like their own child. They feed it the best food, groom them, sing songs to it. The chickens are basically treated like gods before they fight. This also gave rise to many "my c'ock is better than your c'ock" jokes.)

-Fighting?

Education

-Do the children go to school?

-Are certain children more privileged than others and thus go to school while the others don't?

-Is an educated person more valuable to the culture than a normal person?

-Do they find geniuses dangerous?

-What do they do with children born with mental illnesses? Are they killed or taken care of?

-What do the children learn at school?

-How long do they stay in school?

-Is there a gender separation at school? (ie. girls and boys are separated and learn different things, or one gender just isn't allowed to go to school.)

-Do they need to go to school to make it in the world?

-Who teaches them? A nursemaid? A teacher? A priest? A mage?

-Are they very strict in the schools?

-Where are the schools? Are they hard to reach? Are they secluded and hidden?

-What is the school? (A building, a hut, an igloo, a field, a mountain, etc.)

-Are there a lot of them, or just one big one?

-Is there an application process to get into the school?

Language

-Each culture should speak a different language unless there is a common language established by the government that everyone has to learn.

-Dialects. Even within the same city, you can find different dialects.

-Accents. Accents are hugely important and really add another dimension to the story. In Harry Potter, we remember Hagrid from his odd speech. Same with Fleur. Accents really help define characters, so use them. Just don't go overboard so that we can't understand a word your character is saying.

-Each language also has expressions which will be different from the expressions of another language or culture. For example, that c'ock/chicken thing I was talking about above. Eskimos have a ton of words for different kinds of snow, but in mainland America, it's just "snow" or "slush". Depending on the geography and culture of your people, they'll have different sayings and ways to say things. Even among dialects, things change a lot based on specific circumstances. A culture may have gone through a natural disaster in the past, so now they're more close-knit and have more phrases for family and friendship than a culture that is very independent and disjointed.

Transportation

-On foot?

-Cars?

-Wings?

-Carts and horses?

-Teleportation?

How do they get from one place to another?

Economy

-How is their monetary system set up?

-Do they barter and trade items, or do they pay with coins or paper money?

-Do they have a form of credit (like credit cards)?

-IOUs?

-Do people borrow money from each other, or is that seen as shameful?

-What happens if you can't pay a bill?

-Are there free things in the society, such as housing and healthcare and education? Or is everything paid for?

-How do they take care of their poor?

-Is there a lot of poverty?

-How important is it to be rich in that society?

-Do they even have money? Or is everything shared among everyone else?

-Is food rationed among the people, or do they have to buy it themselves?

-Where are goods bought? Marketplaces, malls, shopping districts, street vendors, some kind of magical insta-poofing of goods?

-Can goods be returned or exchanged?

Environment

This goes with the map-making I mentioned above. I took a class on how environment shapes cultures, so I know for a fact that it's VERY important. People living in the desert would live very differently than people living in the tundra than people living on an island.

Art

-Do they paint?

-Write poetry? (there's one culture where males propose to their love with a poem)

-Sculpt?

-Dance?

-Martial arts?

-Tapestries?

-Elaborate chairs (My friend told me that in Cambodia, people show off their wealth by buying very elaborately carved, wooden thrones for themselves.)

-Jewelry?

-Interior decorating?

-Landscaping/gardening?

Music

-Fast music? Slow music?

-What genre of music do they listen to? Dance? Tribal? Classical? Blues? Soul? Rock?

-What instruments do they play?

-Do they have words in their songs?

-Is music strictly played during religious ceremonies/rituals? What about parties? Just for fun or to relax?

Social conduct

-Are women inferior to men and not allowed to look them in the eye? Are men inferior to women?

-Do women woo men or men court women?

-How do marriage proposals works?

-Do they marry for love or for money/social status?

-Are weddings big events in the world?

-Are certain people not allowed to talk with people of higher/lower social status?

-Are there specific gestures one must use when talking to someone of a higher/lower rank? (eg. curtsy or bow to a lord or lady)

-Are people allowed to have physical contact with each other?

-Do men/women practice modesty while in public? (eg. hijabs for Muslim women) At what age does this modesty begin? There's a culture where the children sleep in the same room as their parents, so they watch their parents have sex. Of course, the children will copy them and do the motions with each other like a game. Sexuality is very pronounced in that culture, especially for children and teenagers. Once they marry, though, it's shameful to show sexuality in public, and they become very modest.

-Are certain gestures unacceptable? (Giving someone the middle finger in America is very bad, but a thumbs up is a gesture of encouragement.) Make up your own gestures for your world.

-Vulgarities and swear words? Who's allowed to use them, and who's not? Are there laws against using certain words?

-Are men/women limited to a certain social role? The obvious example is women being confined to the house to cook and clean and men going out to make a living. Please don't use this in your story, though. O.o It's highly offensive and cliche. Be a bit more creative and fun with your social roles.

-Values! What do they value in life? Money? Status? Power? Serenity? Peace? Tranquility? Fun? Drinking?

-How do siblings interact? Is one sibling more important than the other based on age?

-How do parents and children interact? Distantly or warmly and on the same level? Do they see each other as equals or one is better than the other? Are parents supportive of their children, or do the children have to fend for themselves after a certain age?

-Are elders respected or ridiculed? How about babies and children?

-Here's an interesting blurb I found online: "The situation is even more complicated among the English-speaking lower class in Guyana, a South American. Here the typical family is made up of an unmarried woman, her daughters (also unmar­ried), and her daughters' children. Ask children in our own society to pick out their mother and they will point to their biological mother. Ask children in a Guyanese family to pick out their mother and they will point to the person we would call grandmother. The English term applied to the woman who gives birth to a Guyanese child is "auntie" not, "mother." This then represents a case in which there is a role that closely corresponds to the mother role in our own society, but in Guyana that role is occupied by the biological grandmother, not by the biological mother."

If you can take a cultural anthropology class at some point in your life, DO IT. It was so eye-opening to me and showed me a ton of different cultures and lifestyles that I never knew about. Before, the chicken-fighting thing would've disgusted me, but after learning about them and their way of life, it's actually very fascinating! (I still feel bad for the chickens, though...) It really helps with my writing, and my cultures are a lot more diverse and developed because of that class. :)

Research different cultures. Don't guess. Research. Find some really out-there ones rather than mainstream desert folk with camels or rainforest warrior people. The more unique your culture is, the more people will remember it.

Don't be daunted by the world building process. Make it your own! Make it FUN! If you like to draw, actually draw out the landscapes and environments and people and clothes and food. If you like to cook, maybe you can experiment and try cooking the food you find in your story. If you like to sew and fashion design, create costumes based on your world. If you write music, make your own score for your book should it become a movie, and listen to it while you world build. Make it fit the mood of the particular environment you're creating. Heck, you can make origami characters if you want. Make characters out of shells you collected on your last trip to the beach. Sculptures out of your little brother's play-doh. Poems. Use twigs to make a hut if one culture lives in huts. GINGERBREAD HOUSES! You can seriously do anything you want. Whatever helps you get through the world building process with a smile on your face. Making things with your hands will really get your creative juices flowing, and having visuals while planning your world will make it so much more realistic than if you're making it up in your head. You'll be surprised with what you come up with!